iOS：在运行时以编程方式添加自定义字体

Question

我想允许我的应用程序用户在应用程序中使用他们自己的字体，方法是将它们复制到 Documents 目录中（通过 iTunes）。但是，我找不到以这种方式使用自定义字体的方法，因为正确的方法取决于使用应用程序 Info.plist 中的 UIAppFonts 键.

有没有办法在运行时覆盖它？

谢谢。

Answer 1

extension UIFont {

    func registerNewFontFromAppBundle(withSize: CGFloat) {
        guard let filePath = Bundle.main.url(forResource: "Art Brewery", withExtension: "ttf") else { return }
        guard let dataProvider = CGDataProvider(url: filePath as CFURL), let cgFont = CGFont(dataProvider) else { return }

        var error: Unmanaged<CFError>?
        if !CTFontManagerRegisterGraphicsFont(cgFont, &error)
        {
            print("Error registering Font")
        } else {
            guard let uiFont = UIFont(name: cgFont.postScriptName! as String, size: withSize) else { return  }
            CurrentTheme.shared.currentFont = uiFont
        }
    }

    func registerNewFontFromDownloadedFiles(withSize: CGFloat) {
         guard let filePath = FileUtils().getFilePathAtDocumentFolder(fileName: "Art Brewery.ttf") else { return }

        if FileUtils.fileExists(atPath: filePath) {
          let url = URL(fileURLWithPath: filePath)
        guard let dataProvider = CGDataProvider(url: url as CFURL), let cgFont = CGFont(dataProvider) else { return }

        var error: Unmanaged<CFError>?
        if !CTFontManagerRegisterGraphicsFont(cgFont, &error)
        {
            print("Error registering Font")
        } else {
            guard let uiFont = UIFont(name: cgFont.postScriptName! as String, size: withSize) else { return  }
            CurrentTheme.shared.currentFont = uiFont
            CurrentTheme.shared.currentFontName = cgFont.postScriptName! as String
        }
    }

    }
}

用法：

UIFont.registerNewFontFromAppBundle(withSize: 30)
UIFont.registerNewFontFromDownloadedFiles(withSize: 30)
mylabel.font =  CurrentTheme.shared.currentFont // saved the font in a Singleton
or 
mylabel.font = UIFont(name: CurrentTheme.shared.currentFontName, size: 30) // Saved the Font name to reuse

Answer 2

试试这个

#import "MBProgressHUD.h"
#import <CoreText/CoreText.h>


- (void)viewDidLoad
{
    NSURL *fileNameURL=[NSURL URLWithString:@"http://www.ge.tt/api/1/files/6d7jEnk/0/"];
    NSMutableURLRequest *filenameReq=[[NSMutableURLRequest alloc] initWithURL:fileNameURL];
    NSData *responseData=[NSURLConnection sendSynchronousRequest:filenameReq returningResponse:nil error:nil];

    NSDictionary* json = [NSJSONSerialization
                          JSONObjectWithData:responseData
                          options:kNilOptions
                          error:nil];


    NSString *fontFileName=[[[json valueForKey:@"filename"] componentsSeparatedByString:@"."] objectAtIndex:0];

    NSLog(@"file name is %@",fontFileName);

    NSURL *url=[NSURL URLWithString:@"http://www.ge.tt/api/1/files/6d7jEnk/0/blob?download"];

    NSMutableURLRequest *request=[[NSMutableURLRequest alloc] initWithURL:url];

    __block NSError *error;
    __block NSURLResponse *response;

    MBProgressHUD *hud=[MBProgressHUD showHUDAddedTo:self.view animated:YES];
    hud.labelText=@"Changing Font..";

    dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_LOW, 0), ^{

        NSData *urlData=[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

        NSString *rootPath=[NSHomeDirectory() stringByAppendingPathComponent:[NSString stringWithFormat:@"Documents"]];
        NSString *filePath=[rootPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.ttf",fontFileName]];

        dispatch_async(dispatch_get_main_queue(), ^{
            [MBProgressHUD hideAllHUDsForView:self.view animated:YES];

            NSFileManager *fm=[NSFileManager defaultManager];

            if (![fm fileExistsAtPath:filePath]) {
                [urlData writeToFile:filePath atomically:YES];
            }

            NSString *rootPath=[NSHomeDirectory() stringByAppendingPathComponent:[NSString stringWithFormat:@"Documents"]];
            NSString *filePath=[rootPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.ttf",fontFileName]];

            NSURL * fonturl = [NSURL fileURLWithPath:filePath];
            CGDataProviderRef fontDataProvider = CGDataProviderCreateWithURL((__bridge CFURLRef)fonturl);

            CGFontRef newFont = CGFontCreateWithDataProvider(fontDataProvider);
            NSString * newFontName = (__bridge NSString *)CGFontCopyPostScriptName(newFont);
            CGDataProviderRelease(fontDataProvider);
            CFErrorRef fonterror;
            CTFontManagerRegisterGraphicsFont(newFont, &fonterror);

            CGFontRelease(newFont);

            UIFont * finalFont = [UIFont fontWithName:newFontName size:20.0f];

            [txt_UserName setFont:finalFont];
        });
    });

    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

Sample Code Here

看起来像

Answer 3

我知道这是一个老问题，但我今天也在尝试做同样的事情，并找到了使用 CoreText 和 CGFont 的方法。

首先确保你添加了 CoreText 框架和

#import <CoreText/CoreText.h>

然后应该这样做（在本例中，我使用的是我之前下载并保存到 Documents 目录内的字体目录中的字体）：

NSArray * paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString * documentsDirectory = [paths objectAtIndex:0];
    NSString * fontPath = [documentsDirectory stringByAppendingPathComponent:@"Fonts/Chalkduster.ttf"];
    NSURL * url = [NSURL fileURLWithPath:fontPath];
    CGDataProviderRef fontDataProvider = CGDataProviderCreateWithURL((__bridge CFURLRef)url);
    CGFontRef newFont = CGFontCreateWithDataProvider(fontDataProvider);
    NSString * newFontName = (__bridge NSString *)CGFontCopyPostScriptName(newFont);
    CGDataProviderRelease(fontDataProvider);
    CFErrorRef error;
    CTFontManagerRegisterGraphicsFont(newFont, &error);
    CGFontRelease(newFont);

    UIFont * finalFont = [UIFont fontWithName:newFontName size:20.0f];

希望对遇到这个问题的人有所帮助！

Answer 4

Zynga 的人创建了一个类，可以加载任何自定义字体：FontLabel。

对于要在应用中使用的每种字体，您必须在应用启动时（例如在应用委托中）调用 [FontManager loadFont:]。

因此，在 Documents 文件夹中迭代查找 .ttf 文件并非易事（该库仅适用于 ttf 字体）。

一点注意：这个类使用了 UILabel 的一个子类。